So I just purchased THIS and was wondering what exact type of SSD I would need in order to replace the existing small 128gb one with something much more adequate like 500gb or so? I did some research and found that the Samsung 840 is my best option, but there are like 4 types that are listed on their website. From one of the only videos I could find of someone doing something similar with their MacBook pro (late 2012) with retina, it looked to be the msata version, is that correct? Just wanting to purchase the right thing the first time. To clarify as well, you can't just buy the normal sata version and make it fit, or remove it from its case? This is my first Mac but I am fairly computer literate with PCs. Thanks